The definition sentence is the first sentence of a paragraph or section that directly and fully answers the question posed by the heading. It is the single most effective change you can make to content for visibility in generative search engines, because this is exactly the kind of sentence the system looks for and selects. It must meet three conditions: it names the subject rather than using a pronoun, it is understandable without the surrounding text, and it carries specific content, including a number or a condition, where these belong to the topic. A typical mistake is a run-up – an opening paragraph about why the topic matters, followed by the answer only after an image. A second mistake is a circular definition, which explains a term using the term itself. Write so that the first sentence stands on its own, with the rest of the paragraph only expanding on it.
See also: Snippet extraction, Content chunking, Question-based headings.
